Wednesday, June 8, 2011

Holding Tank Venting

Island Girl had no holding tanks originally and only one vent that exited through the bathroom.  I utilized that existing hole along with the original scoop type vent cap for the black tank.  The gray tank vent runs through the wardrobe closet.  For both vents, I decided to use marine through hull fittings.  They make a watertight seal and terminate with barb type ends.  I stayed with barb type fittings for the tank as well and used marine sanitation hose for the actual vent lines.



The inside hole is large to allow access for installing nutplates that will let the vent cap be easily removable for maintenance.  I’ll add a trim plate to cover the hole later.


The vent cap came from a posting on Airforums about finding these neat little caps at some mobile home supply store.


Here the nutplates are installed along with the through hull fittng, ready for some Vulkem for a seal and 6 machine screws for the cap.

I also used Vulkem to add a bit of screen on the top of the fitting to keep the critters out.


Today the toilet got its final install as well.  Other than the flooring install, all the big systems are now in and functional.  Still several hundred little things to finish, but we’ve made it to the point that Island Girl is now totally useable.


  1. What kind of venting pipe did you use for the rest of your venting...rigid PVC pipe or some type of flexible pipe? Thanks in advance...I love your blog!

  2. I used flexible marine sanitation hose, like this stuff:|51|106370|315126&id=150703.

    Easy to use, looks ok, and I was used to using it on the boat. Expensive compared to rigid, but you're not using a lot of it. Rigid pipe works fine too, though.

    Been watching the progress on yours as well. Wish I had Colin fairly close to me.